河西走廊地区植物的区系特征

河西走廊位于甘肃省西部 ,属于典型的内陆干旱区 ,为温带荒漠气候。对河西种子植物区系的组成、特点及性质进行了分析 ,并比较了它与邻近地区植物区系的关系 ,主要结论如下 :1 .种类贫乏 ,本区共有种子植物 52科 ,1 66属 ,32 6种。属种比值高达 50 .92 %。区系具有明显的优势现象 ,仅 5个科就包含了全区植物百分之五十以上的属和种 ;2 .区系中温带成分占绝对优势地位 ,古地中海成分也是重要的组成部分 ;3.本区系的植物在生活型方面以多年生灌木、草本为主。植物区系具有明显的荒漠植物区系特征。 4.河西植物区系成分较古老 ;5.河西地区、塔里木盆地、柴达木盆地、阿拉善地区无论是区系组成或发生方式都非常接近 ,共同组成中国西北荒漠植物区系。

THE FLORISTIC CHARACTERISTICS IN THE AREA OF THE HEXI CORRIDOR

The Hexi Corridor is located in the western part of the Gaansu Province, belonging typical interior arid region and characterized in the temperate desert climate. There are 326 species of seed plants, which belong to 52 families and 166 genera. The floristic characteristics in the area are as follows: 1. Species are poorer, the seed flora in Hexi Corridor consists of 52 families, 166 genera and 326 species. The ratio of genus and species is 50.92%. Floristic dominance is obvious in this area, 5 dominant families contain more than 50 percent of genera and species in the flora;2. The Temperate Zone is superior to numbers of species in the area;3. On the life form of plants of the flora, it is primary perennial herbs and shrubs;the Hexi Corridor has obvious characteristics of Temperate Desert;4. The origin of flora in the Hexi Corridor is older; 5.Quantitative comparison and analysis on florae in the Hexi Corridor and in related area such as Alashan,the Tarim Basin ,the Zhungeer Basin and the Tsaidam Basin indicates that desert flora in Northwestern China is an unity according to their composition and evolution way.